Movable bed

ABSTRACT

An adjustable bed includes a moving mechanism operable to at least tilt or move up and down a platform of the bed, and a safety switch operable to turn ON and OFF in response to movement of the platform. The moving mechanism is suspended when a power ON-OFF state of the safety switch is changed due to displacement of the safety switch from a predetermined position. In addition, a cover may be disposed over the moving mechanism from an outer surface. The safety switch is disposed at a position determined relative to a position of the cover. The power ON-OFF state of the safety switch is changed upon displacement of the cover from the position.

TECHNICAL FIELD

The present invention relates to an adjustable bed for use in nursingcare and the like, and particularly to a safety mechanism of theadjustable bed.

BACKGROUND ART

Generally, adjustable beds used as postural change assistance bedsassist postural changes of a care recipient in order to prevent theoccurrence of decubitus ulcers, more commonly known as bedsore. To thisend, such an adjustable bed tilts at least part of the mattress on whichthe person is lying at an angle (see Japanese Published PatentPublication No. 6-14824). The majority of these types of beds employ amechanism that tilts the mattress toward one side from a horizontalposition.

A driving mechanism (moving mechanism) for the above adjustable bed isnormally provided below a platform of the bed and in an exposedcondition. Consequently, there is a danger that a hand of caregivers,care recipients, or their family members gets caught in the movingmechanism. For the sake of safety in operation, the movable bed needs tobe improved.

DISCLOSURE OF THE INVENTION

The present invention is made in view of the above problems, and aims toprovide an adjustable bed having a safety mechanism allowing a caregiver, a care recipient, and a family member to safely operate the bed.

To address the above problems, the present invention provides anadjustable bed including: a moving mechanism operable to at least tiltor move up and down a platform of the bed; and a safety switch operableto turn ON and OFF in response to movement of the platform. The movingmechanism is suspended when a power ON-OFF state of the safety switch ischanged due to displacement of the safety switch from a predeterminedposition.

Specifically, the adjustable bed may further include a changeover memberoperable, in response to movement of the platform, to change the powerON-OFF state of the safety switch.

With the adjustable bed having the above structure, first of all, themoving mechanism is made to stop operating upon displacement of thesafety switch from the predetermined position. Thus, in the case where aforeign object or a part of human body gets caught in the movingmechanism, the moving mechanism stops operating, before beingexcessively stressed and damaged. As described above, the presentinvention effectively restricts unnecessary accesses to the movingmechanism. In addition, the present invention provides significantlyimproved security by immediately suspending the operation of theadjustable bed when a foreign object or a part of human body gets caughtin the moving mechanism.

Second of all, the immediate suspension of the bed operation achievesthe effect of preventing an excessive stress to the moving mechanism.

Specifically, the adjustable bed may further include a cover disposed soas to cover an outer surface of the moving mechanism. The safety switchis disposed at a position determined relative to a position of thecover. The power ON-OFF state of the safety switch is changed upondisplacement of the cover from the position.

Further, the moving mechanism may include: a flexing mechanism operableto flex the platform to form a flexion position that includes at leastone of an upper body elevation and a knee flexion; and a tiltingmechanism operable to laterally tilt the platform. The flexing andtilting mechanisms are each operable when the other mechanism isoperating. The cover is mounted to the tilting mechanism.

Still further, the adjustable bed may further include: a side memberdisposed on a side of the platform, and a side member raising mechanismfor raising the side member relative to the platform. The tiltingmechanism downwardly tilts the platform toward the side member raised bythe side member raising mechanism.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an oblique view of an adjustable bed according to anembodiment 1 of the present invention;

FIGS. 2A-2C are sectional views of the bed showing an adjustable stageand its nearby portion;

FIG. 3 is a schematic top view of the bed;

FIG. 4 is an oblique view of a fixed stage;

FIG. 5 is an oblique view of the bed (with left side members risen);

FIG. 6 is an oblique view of the bed (in a flexion position);

FIG. 7 is an oblique view of the bed (downwardly tilted toward theleft);

FIG. 8A is a schematic side view of a bed frame (in a horizontalposition), FIG. 8B is a schematic side view of the bed frame (in aflexion position), FIG. 8C is a schematic side view of the bed (in ahorizontal position), and FIG. 8D is a schematic side view of the bed(in a flexion position), all seen lengthwise;

FIG. 9 is an oblique view of the fixed stage provided with mechanicscovers;

FIG. 10A is a block diagram of a control unit, and FIG. 10B is a viewshowing the structure around the mechanics cover; and

FIG. 11A is an oblique view showing an adjustable bed (modification),and FIG. 11B is an oblique view sowing operation of the modifiedadjustable bed.

BEST MODE FOR CARRYING OUT THE INVENTION 1. Embodiment 1

Hereinafter, a description is first given to the overall structure of anadjustable bed according to an embodiment 1 of the present invention.Then, a detailed description is given to the safety mechanism (utilizinga mechanics cover) of the bed.

1-1. Structure of Postural Change Assistance Bed

FIG. 1 is an oblique view showing the overall structure of an adjustablebed 1 according to the embodiment 1 of the present invention.

The bed 1 shown in the figure is constituted such that a bed frame 10 isplaced on an adjustable stage 20 which in turn is placed on a fixedstage 30.

The bed frame 10 has a surface area that is composed of four platformmembers 11 a-11 d for suitably receiving four articulations (the upperbody, lower body, upper leg, and lower leg regions) of the carerecipient's body when lying on the bed. The four platform members 11a-11 d are movably coupled to constitute a coupled platform. Morespecifically, the bed frame 10 is composed of an upper-body member 11 a,a lower-back member 11 b, an upper-leg member 11 c, and a lower-legmember 11 d coupled in the stated order.

The lower-back member 11 b is directly secured to the adjustable stage20 by welding, for example. Thus, the bed frame 10 is not detachablefrom the adjustable stage 20. The platform members 11 a-11 d are eachflanked by respective pairs of side members 12Ra-12Rd and 12La-12Ldcoupled thereto from the right and left. The side members 12Ra-12Rd and12La-12Ld support the care recipient's body from the side at the time ofpostural change. The upper-body member 11 a of the bed frame 10 iscoupled to the shaft of a direct-acting actuator M1 via an L-shapedcoupler 211, whereas the upper-leg member 11 c is coupled to the shaftof a direct-acting actuator M2 via an L-shaped coupler 212. Theactuators M1 and M2 are disposed on a center beam 21A of the adjustablestage 20. (See FIG. 3 showing a top view of the bed.) Thus, by theaction of the actuators M1 and M2, the bed's profile is adjusted tobring the care recipient into a flexion posture (see FIG. 6 showing astate of the bed and FIG. 8B showing a side view of the bed).

Note that each of the platform members 11 a-11 d as well as the sidemembers 12Ra-12Rd and 12La-12Ld are covered by wire mesh. In thedrawings, however, the wire mesh is omitted to show the frames of theplatform members 11 a-11 d and of the side members 12Ra-12Rd and12La-12Ld in order to clearly illustrate the structure and operation ofthe bed. In addition, although the fixed stage 30 is provided withmechanics covers 370R and 370L serving as a safety mechanism, themechanics covers 370R and 370L are shown in FIGS. 9 and onward. In FIGS.6-8 showing bed operations, in addition, some of the constituentelements, such as side-member support frames 24R and 24L, are omitted soas to clearly illustrate the bed operations.

As mentioned above, among the side members 12Ra-12Rd and 12La-12Ld, theside members 12Rc and 12Lc are located at positions corresponding to theupper-legs of the care recipient. The side members 12Rc and 12Lc areeach provided, on the surface, with an envelope-like pocket that isapproximately the same size as the side members 12Rc and 12Lc (see FIG.8D showing a side view of the bed). In addition, the side members 12Rdand 12Ld located at positions corresponding to the lower-legs of thecare recipient are coupled, along the edge, to fan-shaped members 13Rand 13L, respectively (13R is not illustrated). Normally, the fan-shapedmembers 13R and 13L are housed in the above-mentioned pockets of theside members 12Rc and 12Lc. When the bed frame 10 is adjusted to aposition for the flexion posture, the fan-shaped members 13R and 13Lcome out of the pockets to support the care recipient's knees.

The adjustable stage 20 has a rectangular frame construction formed fromthe center beam 21A, side beams 21R and 21L, and two parallel frameseach connecting the respective ends of the center and side beams. Asillustrated in the figures, the side beams 21R and 21L are provided withrollers 200, 201, 202, and 203 allowing sliding movement of the sidebeams 21R and 21L along a roller slide frame 300 in the direction of y(the roller 203 is hidden beneath the bed frame 10).

The side beam 21R of the adjustable stage 20 is provided with a pair ofbars 22R and 23R extending along the side beam 21R, as well as withconnecting bars 231R and 232R. The pair of bars 22R and 23R and theconnecting bars 231R and 232R together constitute a ladder-likeside-member support frame 24R. Similarly, the side beam 21L is providedwith a ladder-like side-member support frame 24L constituted of a pairof bars 22L and 23L extending along the side frame 21L, as well as ofconnecting bars 231L and 232L. The bars 22R, 23R, 22L, and 23L each havebends defining a concave along its lengthwise direction. The concavesare formed at positions where the side members 12Rb and 12Lb engageagainst the side-member support frames 24R and 24L, respectively.Consequently, the side member 12Rb fits within the concave (see FIG. 3showing the top view of bed). Being fit within the respective concaves,the side members 12Rb and 12Lb obstruct neither the side members 12Raand 12La nor the side members 12Rc and 12Lc in the thickness directionseven when bed frame 10 is adjusted to the flexion position. In addition,the bar 22R is coupled to the side beam 21R by couplers 236Ra and 236Rb,and the bar 22L is coupled to the side beam 21L by couplers 236La and236Lb. Owing to the coupling to the side beams 21R and 21L, the bars 22Rand 22L are allowed to freely rotate on their axes while remainingsecured to the side beams 21R and 21L. By rotating the side-membersupport frames 24R and 24L on the axes of the rotating bars 22R and 22Lto a vertical position (in the z direction), the side members 12Ra-12Rdand 12La-12Ld are pushed upward to a risen position.

FIGS. 2A-2C are schematic sectional views of the adjustable stage 20 andthe bed frame 10, taken laterally across the lower-back member 11 c toillustrate the operations of the actuators. As shown in the figures, theadjustable stage 20 is provided with the above-described actuators M1and M2 for changing the profile of the bed frame 10. In addition, theadjustable stage 20 is provided with direct-acting actuators M3R and M3Ldisposed in laterally symmetric relation to the center beam 21A.Specifically, the actuators M3R and M3L are disposed on the right andleft of the y direction correspondingly to the couplers 236Ra and 236La.The end of each shaft of the actuators M3R and M3L is respectivelycoupled to the L-shaped members 235R and 235L, which are hung from therespective rotating bars 22R and 22L. With this structure, when theshaft of each of the actuators M3R and M3L extends, the L-shaped members235R and 235L and the bars 23R and 23L rotate on the rotating bars 22Rand 22L. As a result, the side-member support frames 24R and 24L risefrom the horizontal surface of the bed to form a right angle withrespect to the bed surface (FIGS. 2A→2B→2C).

On the underside of the side beams 21R and 21L, stage bars 27R and 27Lare provided. On the fixed stage 30 are provided stage-bar receives 36Rand 36L having a U-shaped cross section to receive the stage bars 27Rand 27L, respectively. Reverse L-shape pawls are disposed inside each ofthe stage-bar bearings 36R and 36L along the width-wise direction. Thepawls engage around the stage bars 27R and 27L received in the stage-barbearings 36R and 36L, so that the adjustable stage 20 is fixed againstthe vertical movement. Yet, when the adjustable stage 20 is tilted, oneof the stage bars 27R and 27L are lifted and detached from therespective one of the stage-bar bearings 36R and 36L.

FIG. 4 is an oblique view of the fixed stage 30. The fixed stage 30 isprovided with a rectangular frame 31. One of a pair of shorter oppositesides of the rectangular frame 31 constitutes the roller slide frame 300along which the rollers 200-203 of the adjustable stage 20 slide backand forth. Side beams 32R and 32L of the fixed stage 30 constitutesliding channels substantially defining a laterally oriented U-shape incross section with their openings facing each other. Support arms 354Rand 356R are both coupled at one end to the stage-bar bearings 36R, andto the side beam 32R at the other end in a manner freely slidable alongthe side beam 32R. Similarly, support arms 354L and 356L are bothcoupled at one end to the stage-bar bearing 36L, and to the side beam32L at the other end in a manner freely slidable along the side beam32L. In addition, the support arms 354R, 356R, 354L, and 356L areseparately linked to reverse L-shaped rotating arms 351R, 352R, 351L,and 352L. The rotating arms 351R, 352R, 351L, and 352L are coupled atone end to the side beams 32R and 32L, and also to horizontal links 353Rand 353L the other end. An actuator M4R is disposed at an angle betweenthe stage-bar bearing 36R and the horizontal link 353R. Similarly, anactuator M4L is disposed at an angle between the stage-bar bearing 36Land the horizontal link 353L. With the above arrangement, parallelogrammechanisms 35R and 35L are constituted one on each lateral side of thefixed stage 30. With parallelogram mechanisms 35R and 35L employing ahorizontal sliding mechanism, the rotating arms 351R, 352R, 351L, and352L make a circular motion about the linked points on the side beams32R and 32L. In response to the circular motion of the rotating arms351R, 352R, 351L, and 352L, the ends of the support arms 354R, 356R,354L, and 356L move back and forth within the grooves of the side beams32R and 32L. When the support arms 354R, 356R, 354L, and 356L swingtoward a vertical position, the adjustable stage 20 as well as the bedframe 10 supported by the stage-bar bearings 36R and 36L verticallymoves away from or toward the right and left sides of fixed stage 30.That is to say, the bed 1 is capable of up and down movement within anarrow space and is of a space-saving configuration. In addition, therollers 200-203 and the parallelogram mechanisms 35R and 35L enable thepostural change operations without requiring much space. By driving oneof the parallelogram mechanisms 35R and 35L at a time for the movementof either of the side beams 32R and 32L, the bed 1 is adjusted itsprofile for the postural change from a supine posture to a lateralside-lying posture. On the other hand, driving both the parallelogrammechanisms 35R and 35L at the same time, the High/Low operation of thebed 1 is carried out.

The drive of the actuators M1, M2, M3R, and M3L are controlled by amotor driver 403 and a CPU 401 provided with in a control unit 400, allof which are described later. The drive setting includingpre-programming may be made automatically or manually by the caregiverusing a controller (not illustrated) at hand. Furthermore, with the useof a remote controller of an infrared, wired, or wireless type, thedrive setting may be made by the care recipient.

Note that the structure of the adjustable bed 1 described above 1 is oneexample. As later described, the mechanics covers 370R and 370L, whichare a feature of the present invention, may be applied to an adjustablebed having a different structure.

1-2. Operations of Adjustable Bed (Supine→Lateral)

The adjustable bed having the above structure is put to actual use witha mattress overlaid on the bed frame 10. The detailed description of themattress is described later in detail. In the normal profile, theplatform members 11 a-11 d and the side members 12Ra-12Rd and 12La-12Ldare all disposed substantially horizontal and together constitute a bedsurface, as shown in FIG. 1.

First, a user (caregiver, in this example) selects and executes on thecontroller a menu for a postural change from a supine and flexionposture to a left side-lying and flexion posture. In response, theactuator M3L attached to the adjustable stage 20 is activated andextends its shaft. Then, the bar 23L and the L-shaped member 235Lcoupled to the end of the shaft rotate about the rotating bar 22L. As aresult, the side-member support frame 24L comes to rise and form a rightangle with respect to the horizontal bed surface. (See FIGS. 2A→2B→2Cillustrating the actuator operations; FIG. 5 showing the state of theside members 12La-12Ld in a raised state; and FIG. 8C showing the sideview of the bed in the raised state).

Next, the direct-acting actuators M1 and M2 attached to the center beam21A of the adjustable stage 20 extend their shafts, thereby separatelypushing, via the L-shaped couplers 211 and 212, the upper-body member 11a and the lower-back member 11 c of the bed frame 10 from the rear. As aresult, the bed is adjusted to a position for the care recipient to bein a flexion posture with the upper body raised and the knees up (seeFIG. 6 showing an oblique view of the bed in the flexion position; andFIGS. 8→8B showing side views of the bed in this state). With thepositional change of the platform members 11 a-11 d, the side members12La-12Ld also change their positions accordingly. As a result, thefan-shaped members 13L comes out from the pocket of the side member 12Lcto support parts of the mattress around the care recipient's knees (seeFIGS. 8C→8D showing side views of the bed in this state).

When the above operations bring the bed to the flexion position with theleft side members risen up, the actuator M4R disposed on the side beam32R of the fixed stage 30 then extends its shaft to widen the distancebetween the stage-bar bearing 36R and the horizontal link 353R. As aresult, the support arms 354R and 356R slide in the sliding groove ofthe side beam 32R to a more upright position. Thus, the parallelogrammechanism 35R works. At this stage, the two support arms 354R and 356Ror 354L and 356L come to vertically lift the right side of theadjustable stage 20 in response to the circular motion of the tworotating arms 351R and 352R or 351L and 352L. Thus, the right side ofthe adjustable stage 20 is vertically lifted to a level higher than thefixed stage 30, thereby causing the rollers 201-204 to run on the rollerslide frame 300. Consequently, the bed frame 10 downwardly inclinestoward the side beam 32L of the fixed stage 30, i.e. toward the leftside of the bed (see FIG. 7 showing the bed in the inclined state).Preferably, the inclination angle of the bed to the horizontal surfacefalls within the range of about 30° to 70°, for example about 50°.

With the changes in the profile of the bed frame 10, the care recipientis assisted to smoothly change the posture from a supine to a lateralposition while being supported by the platform members 11 a-11 d and theside members 12La-12Ld, after firstly being placed in a supine flexionposition with the upper body raised and the knees flexed. The abovepostural change is smoothly carried out as if the care recipient' bodyrolls along the hands of caregiver put to support the care recipient.

Now, a description is given to a main feature of the present invention.

1-3. Safety Mechanism of Adjustable Bed

FIG. 9 is a view showing the adjustable bed provided with a safetymechanism. More specifically, the figure shows the structure around thefixed stage of the bed. In the example shown in the figure, theparallelogram mechanisms 35R and 35L are provided with the mechanicscover 370R and 370L, respectively. Each mechanics cover is shaped like aplate and covers the respective parallelogram mechanism from outside.

In one specific example, the main body of each of the mechanics covers370R and 370L is made of a styrene board. The mechanics cover 370R isattached to the stage-bar bearing 36R by engagement between U-shapedmetal pieces 372R and 373R (not illustrated). Similarly, the mechanicscover 370L is attached to the stage-bar bearing 36L by engagementbetween U-shaped metal pieces 372L and 373L. Thus, the mechanics covers370R and 370L are hung upon the respective stage-bar bearings 36R and36L along the lengthwise direction. Between each pair of engaging metalpieces 372R and 373R as well as 372L and 372R, a safety switch isprovided. In this example, micro switches MSR and MSL (the micro switchMSL is not illustrated) are disposed between the respective pairs ofmetal pieces. As shown in FIG. 10A, the state of the micro switches MSRand MSL (SW R and SW L) is monitored by the CPU 401 via the I/O 402 ofthe control unit 400. Normally, the micro switches MSR and MSL are in ONstate under the weight of the mechanics covers 370R and 370L. In thecase where any foreign object (an arm of the caregiver, for example)lifts either of the mechanics covers 370R and 370L from underneath, acorresponding one of the metal piece pairs is disengaged. As a result, acorresponding one of the micro switches MSR and MSL is switched OFF,thereby stop issuing a detection signal. Upon detecting the absence ofdetection signal, the CPU 401 of the control unit 400 stops the drive ofthe actuators M4R and M4L in the parallelogram mechanisms 35R and 35L.As described above, the mechanics covers 370R and 370L function aselements triggering the ON/OFF state changeover of the micro switchesMSR and MSL.

Although not illustrated in FIG. 10A, the actuators M1 and M2, which aredriven to change the bed to a Gatch position, are also made to stop.Furthermore, although the micro switches MSR and MSL are employed inthis example, other types of switches are applicable, including a pushswitch, a lever switch, and a slide switch.

With the above operations, the drive of the bed is immediately suspendedin the case where the caregiver, care recipient, or family memberaccidentally places his hand in or around the parallelogram mechanismswhile the bed is being driven. It is because when either of themechanics covers 370R and 370L is lifted as a result of a contact withthe hand, the pair of U-shaped metal pieces 372R and 373R or 372L and373L is disengaged. With the above safety mechanism, the adjustable bedensures significantly improved safety.

As above, the provision of the mechanics covers 370R and 370L offers asafety measurement to prevent that the caregiver, the care recipient, ora family member accidentally places a part of the body (a limb, forexample) inside the bed to reach the moving parts, such as theparallelogram mechanisms 35R and 35L. In addition, the provision of themechanics covers 370R and 370L serves to hide the moving parts, such asthe parallelogram mechanisms 35R and 35L, from view.

Note that the present invention is not limited to the aboveconfiguration of suspending the drive of the bed upon disengagement ofthe pair of U-shaped metal pieces 372R and 373R or 372L and 373L.Alternatively, the present invention may be configured so as to switchoff the drive of the parallelogram mechanisms 35R and 35L based on thedetection signal from the micro switches, at the time when the pair ofU-shaped metal pieces is lifted. It should be noted, in addition, thatthe present invention is not limited to the configuration employing theU-shaped metal pieces 372R, 373R, 372L, and 373L. Any configuration isapplicable as long as the displacement of mechanics covers from thepredetermined positions (where the mechanics covers are normally hungon) is detected, and the parallelogram mechanisms 35R and 35L areswitched off in response to the detection signal.

Turning now to the size of the mechanics covers 370R and 370L, it issatisfactory that the mechanics covers 370R and 370L cover theparallelogram mechanisms 35R and 35L, as shown in FIG. 9. For furtherimproving the safety, the mechanics covers 370R and 370L may be as largein lengthwise as the adjustable stage 20 in the direction X.

In addition, the above description is directed to the example in whichthe mechanics covers composed of styrene boards are disposed to coverthe moving parts including the parallelogram mechanisms 35R and 35L fromoutside. Yet, when it is not so intensively requested to block themoving parts (i.e. when the mechanics covers 370R and 370L may usedsimply as means for triggering the micro switches MSR and MSL), themechanics covers 370R and 370L may be composed of metallic or plasticframes (the overall size of the frames is preferably equal to themechanics covers 370R and 370L as in the above example). Alternatively,a lattice or a plate made of a translucent resin may be applicable. Thematerial and configuration of the mechanics covers 370R and 370L may besuitably altered.

In addition, the above example is directed to the case where the microswitches MSR and MSL are arranged between the pairs of the U-shapedmetal pieces 372R and 372L as well as 373L and 373R that in turnarranged at the upper part of the parallelogram mechanisms 35R and 35L.Alternatively, however, the micro switches MSR and MSL may be arrangedon any of the following elements 353R and 353L, 354R and 354L and 356Rand 356L. In this case, instead of the mechanics covers 370R and 370L,the micro switches MSR and MSL may be each provided with a pole-likemember or wire-like member as the triggering mechanism used inconjunction with, for example, the above-described U-shape metal pieces.

1-4. Supplemental Notes

The above embodiment 1 is directed to the bed structure employing theparallelogram mechanisms. Yet, the present invention is not limited tosuch a structure, and the adjustable bed may be of another structure asfollows.

An adjustable bed shown in FIG. 11A is provided with vertically disposeddirect-acting actuators. Using elevating mechanisms, either of left andright side members is moved up or down, thereby inclining a platformplaced on an adjustable stage. The bed is provided with a rectangularframe serving as a fixed stage, and a pair of direct-acting actuatorshaving columnar shape. On the top of the actuators is provided a bedframe supported by a flexible frame. Similarly to the embodiment 1, theplatform of the bed is constituted by coupling a plurality of platformmembers, so as to receive the upper body, lower back, upper leg, andlower leg regions of the care recipient's body. Among the platformmembers, the one receiving the lower back of the care recipient's bodyis securely fixed to the platform frame serving as the movable frame. Onthe underside of the platform is provided a driving unit for driving anactuator mechanism used to change the bed to a flexion position.

The mechanics covers serving as a safety mechanism according to thepresent invention are disposed along a lateral side of each columnaractuator.

On the top of the columnar actuators, side members of the bed aredisposed. The side members each have a housing slot formed therein, anda pullout wall is housed in each housing slot. The pullout walls arecoupled to each other along a lengthwise direction of the bed. The sidemembers are coupled to the adjustable stage via the respective pulloutwalls. Each pullout wall is biased toward inside the housing slot by atension spring, for example. When the force puling out the pullout wallsweakens, the pullout walls are automatically retracted back into thehousing slots.

According to the modified adjustable bed, at the time of driving thebed, the coupled platform is first changed its profile to a flexionposition, as shown in FIG. 11B. Then, one of the columnar actuatorsstarts operating to descend either right or left side members. As aresult, the adjustable stage, as well as the coupled platform, islaterally inclined. On the downwardly inclined lateral side of theadjustable stage, the pullout walls are pulled out from the housingslots to rise relatively to the coupled platform. In other words, thepullout walls are hung from the coupled platform so as to form a smallerangle therebetween. Correspondingly to the above profile change, theside members come to rise relative to the surface of the platform. Withthe above operations, the care recipient is suitably supported from theside by the pullout walls while in a flexion posture, thereby assistingthe postural change as effectively as the embodiment 1. With this bedstructure, the mechanics covers operate just as in the embodiment landprovide a suitable safety mechanism.

In the above embodiment, the micro switches are normally ON, and turnedOFF upon detection of a foreign object. Yet, the present invention isnot limited to the above structure. The micro switches may be normallyOFF, and turned ON upon detection of a foreign object. The ON/OFF stateof the micro switches may be adapted to either way, depending on thecircuitry configuration.

Furthermore, according to the above embodiment, it is the CPU 401 thatcontrols the drive of the actuators. Yet, the drive control may becarried out without a CPU through the hardware structure (for example, astructure that interrupts the power supply to the driving systems suchas the actuators when any of the micro switches are tuned OFF)

INDUSTRIAL APPLICABILITY

The adjustable bed according to the present invention is suitably usedas a nursing care bed or a reclining bed.

1. An adjustable bed, comprising: a moving mechanism operable to at least tilt or move up and down a platform of the bed; and a safety switch operable to turn on and off an operation of the moving mechanism, wherein the safety switch is normally under pressure, and upon release of the pressure, a power ON-OFF state of the safety switch is changed to suspend the operation of the moving mechanism.
 2. The adjustable bed according to claim 1, further comprising a changeover member operable, in response to movement of the platform, to change the power ON-OFF state of the safety switch.
 3. The adjustable bed according to claim 1, further comprising a cover disposed so as to cover an outer surface of the moving mechanism, wherein the safety switch is disposed at a position determined relative to a position of the cover, and the power ON-OFF state of the safety switch is changed upon displacement of the cover from the position.
 4. The adjustable bed according to claim 3, wherein the moving mechanism includes: a flexing mechanism operable to flex the platform to form a flexion position that includes at least one of an upper body elevation and a knee flexion; and a tilting mechanism operable to laterally tilt the platform, the flexing and tilting mechanisms are each operable when the other mechanism is operating, and the cover is mounted to the tilting mechanism.
 5. The adjustable bed according to claim 1, further comprising: a side member disposed on a side of the platform, and a side member raising mechanism for raising the side member relative to the platform, wherein the tilting mechanism downwardly tilts the platform toward the side member raised by the side member raising mechanism. 